Electrical equipment that is connected to the power system and consumes electrical power is known as an electrical load. electrical loads are classified into three types that are resistive loads, capacitive loads, and inductive loads. they are differentiated from each other by their leading and lagging phase relationship between the voltage and current. all three types of electrical loads are explained below with example of resistive, capacitive, and inductive loads.
Resistive loads
The resistance of the conductor creates friction and reduces the amount of current flowing through it. due to this electrical friction, heat and light are produced. Examples of resistive loads are light bulbs, toasters, and electric hot water heaters.
Examples of resistive loads are heaters, and light bulbs that draw sinusoidal current from the power system. resistive loads take power in such a manner that current and voltage wave remains in the same phase hence power factor of resistive loads remains unity.
Inductive Electrical loads
Electrical loads that consume only reactive power are called inductive loads. in the case of inductive load, the voltage and current are out of phase with each other.
The current waveform lags behind the voltage waveform by 90deg as shown in the diagram.
The power factor of the inductive load is lagging.
Inductive-type loads required a magnetic field to perform their work. Examples of inductive loads are hairdryers, fans, vacuum cleaners, and induction motors, all types of motors are inductive loads.
In an induction motor, to perform work it draws real power from an electrical source in addition to real power, reactive power is also taken from the power system to produce the magnetic field. therefore the total power consumed by the electrical motor in addition to real KiloWatt and reactive KVAR.
Capacitive Electrical Load
The capacitor is a component made of two metal plates separated by dielectric material. this dielectric material charges when voltage is applied across the metal plates.
Current in capacitive load leads to the voltage because of the time it takes the dielectric material to charge up to full voltage from the charging current.
An example of a capacitive load is the capacitor bank. the power factor of the capacitive loads is leading means the current leads the voltage by 90deg whereas in inductive load current lags behind the voltage by 90deg.
The voltage and current waveform of the capacitive load is shown in the diagram.
